Answer:
2-
Step-by-step explanation:
Net charge describes the overall negative or positive charge of an atom or compound. Also, note that it is common in chemistry to write the sign of the charge after the number. Nevertheless, the charges +1 and 1+ are completely the same.
Calculating Charge
To find the charge of an atom you should look at the number of protons and electrons. Since neutrons have a neutral charge, aka no charge, they do not factor into net charge. On the other hand, protons have a positive charge and electrons have a negative charge. Each proton has a 1+ charge and each electron has a 1- charge.
To find the net charge find the total charge of the electrons and the total charge of protons, then add them together. Since there are 9 protons, the total proton charge is 9+. There are 11 electrons, so the total electron charge is 11-. For the purposes of doing the math, we can move the sign to the front.
Thus, the net charge is 2-.
Anions and Cations
To work with ions it is important to understand the vocabulary surrounding ions. Firstly, negative ions, like the one described in the question, are called anions. You can remember this as "A Negative ION". Also, positive ions, ions with positive net charges, are called cations. You can remember that the "t" looks like a plus sign.